Request For Comments - RFC1461

Network Working Group D. Throop
Request for Comments: 1461 Data General Corporation
May 1993
SNMPMIB extension for Multiprotocol Interconnect over X.25
Status of this Memo
This RFC specifies an IAB standards track protocol for the Internet
community, and requests discussion and suggestions for improvements.
Please refer to the current edition of the "IAB Official Protocol
Standards" for the standardization state and status of this protocol.
Distribution of this memo is unlimited.
Abstract
This memo defines a portion of the Management Information Base (MIB)
for use with network management protocols in TCP/IP-based internets.
In particular, it defines objects for managing Multiprotocol
Interconnect (including IP) traffic carried over X.25. The objects
defined here, along with the objects in the "SNMP MIB extension for
the Packet Layer of X.25"[8], "SNMP MIB extension for LAPB"[7], and
the "Definitions of Managed Objects for RS-232-like Hardware Devices"
[6], combine to allow management of the traffic over an X.25 protocol
stack.
Table of Contents
1.The Network Management Framework ......................... 12. Objects .................................................. 22.1 Format of Definitions ................................... 23. Overview ................................................. 33.1 Scope ................................................... 33.2 Structure of MIB objects ................................ 34. Definitions .............................................. 45.Acknowledgements ......................................... 196. References ............................................... 207. Security Considerations ................................... 218. Author's Address ......................................... 211.The Network Management Framework
The Internet-standard Network Management Framework consists of three
components. These components give the rules for defining objects,
the definitions of objects, and the protocol for manipulating
objects.
Throop [Page 1]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
The network management framework structures objects in an abstract
information tree. The branches of the tree name objects and the
leaves of the tree contain the values manipulated to effect
management. This tree is called the Management Information Base or
MIB. The concepts of this tree are given in STD 16, RFC 1155, "The
Structure of Management Information" or SMI [1]. The SMI defines the
trunk of the tree and the types of objects used when defining the
leaves. STD 16, RFC 1212, "Towards Concise MIB Definitions" [3],
defines a more concise description mechanism that preserves all the
principals of the SMI.
The core MIB definitions for the Internet suite of protocols can be
found in STD 17, RFC 1213 [4], "Management Information Base for
Network Management of TCP/IP-based internets".
STD 15, RFC 1157 [2] defines the SNMP protocol itself. The protocol
defines how to manipulate the objects in a remote MIB.
The tree structure of the MIB allows new objects to be defined for
the purpose of experimentation and evaluation.
2. Objects
The definition of an object in the MIB requires an object name and
type. Object names and types are defined using the subset of
Abstract Syntax Notation One (ASN.1) [5] defined in the SMI [1].
Objects are named using ASN.1 object identifiers, administratively
assigned names, to specify object types. The object name, together
with an optional object instance, uniquely identifies a specific
instance of an object. For human convenience, we often use a textual
string, termed the descriptor, to refer to objects.
Objects also have a syntax that defines the abstract data structure
corresponding to that object type. The ASN.1 language [5] provides
the primitives used for this purpose. The SMI [1] purposely
restricts the ASN.1 constructs which may be used for simplicity and
ease of implementation.
2.1. Format of Definitions
Section 4 contains the specification of all object types contained in
this MIB module. The object types are defined using the conventions
defined in the SMI, as amended by the extensions specified in
"Towards Concise MIB Definitions" [3].
Throop [Page 2]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
3. Overview
3.1. Scope
Instances of the objects defined below provide management information
for Multiprotocol Interconnect traffic on X.25 as defined in RFC 1356
[9]. That RFC describes how X.25 can be used to exchange IP or
network level protocols. The multiprotocol packets (IP, CLNP, ES-IS,
or SNAP) are encapsulated in X.25 frames for transmission between
nodes. All nodes that implement RFC 1356 must implement this MIB.
The objects in this MIB apply to the software in the node that
manages X.25 connections and performs the protocol encapsulation. A
node in this usage maybe the end node source or destination host for
the packet, or it may be a router or bridge responsible for
forwarding the packet. Since RFC 1356 requires X.25, nodes that
implement RFC 1356 must also implement the X.25 MIB, RFC 1382.
This MIB only applies to Multiprotocol Interconnect over X.25
service. It does not apply to other software that may also use X.25
(for example PAD). Thus the presence, absence, or operation of such
software will not directly affect any of these objects. (However
connections in use by that software will appear in the X.25 MIB).
3.2. Structure of MIB objects
The objects of this MIB are organized into three tables: the
mioxPleTable, the mioxPeerTable, and the mioxPeerEncTable. All
objects in all tables are mandatory for conformance with this MIB.
The mioxPleTable defines information relative to an interface used to
carry Multiprotocol Interconnect traffic over X.25. Such interfaces
are identified by an ifType object in the Internet-standard MIB [4]
of ddn-x25 or rfc877-x25. Interfaces of type ddn-x25 have a self
contained algorithm for translating between IP addresses and X.121
addresses. Interfaces of type rfc877-x25 do not have such an
algorithm. Note that not all X.25 Interfaces will be used to carry
Multiprotocol Interconnect traffic. Those interfaces not carrying
such traffic will not have entries in the mioxPleTable. The entries
in the mioxPleTable are only for interfaces that do carry
Multiprotocol Interconnect traffic over X.25. Entries in the
mioxPleTable are indexed by ifIndex to make it easy to find the
mioxPleTable entry for an interface.
The mioxPeerTable contains information needed to contact an X.25 Peer
to exchange packets. This includes information such as the X.121
address of the peer and a pointer to the X.25 call parameters needed
to place the call. The instance identifiers used for the objects in
Throop [Page 3]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
this table are independent of any interface or other tables defined
outside this MIB. This table contains the ifIndex value of the X.25
interface to use to call a peer.
The mioxPeerEncTable contains information about the encapsulation
type used to communicate with a peer. This table is an extension of
the mioxPeerTable in its instance identification. Each entry in the
mioxPeerTable may have zero or more entries in this table. This
table will not have any entries that do not have correspondent
entries in mioxPeerTable.
4. Definitions
MIOX25-MIB DEFINITIONS ::= BEGIN
IMPORTS
Counter,
TimeTicks
FROM RFC1155-SMI
OBJECT-TYPE
FROM RFC-1212
DisplayString, transmission,
ifIndex
FROM RFC1213-MIB
InstancePointer
FROM RFC1316-MIB
X121Address
FROM RFC1382-MIB
PositiveInteger
FROM RFC1381-MIB;
-- IP over X.25MIB
miox OBJECT IDENTIFIER ::= { transmission 38 }
mioxPle OBJECT IDENTIFIER ::= { miox 1 }
mioxPeer OBJECT IDENTIFIER ::= { miox 2 }
-- ###########################################################
-- Ple Table
-- ###########################################################
-- Systems that implement RFC 1356 must also implement
-- all objects in this group.
mioxPleTable OBJECT-TYPE
SYNTAX SEQUENCE OF MioxPleEntry
Throop [Page 4]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
PositiveInteger,
mioxPleDefaultPeerId
InstancePointer
}
mioxPleMaxCircuits OBJECT-TYPE
SYNTAX INTEGER (0..2147483647)
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The maximum number of X.25 circuits that
can be open at one time for this interface.
A value of zero indicates the interface will
not allow any additional circuits (as it may
soon be shutdown). A value of 2147483647
allows an unlimited number of circuits."
::= { mioxPleEntry 1 }
mioxPleRefusedConnections OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of X.25 calls from a remote
systems to this system that were cleared by
this system. The interface instance should
identify the X.25 interface the call came in
on."
::= { mioxPleEntry 2 }
mioxPleEnAddrToX121LkupFlrs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times a translation from an
Encapsulated Address to an X.121 address
failed to find a corresponding X.121
address. Encapsulated addresses can be
looked up in the mioxPeerTable or translated
via an algorithm as for the DDN. Addresses
that are successfully recognized do not
increment this counter. Addresses that are
not recognized (reflecting an abnormal
packet delivery condition) increment this
counter.
If an address translation fails, it may be
Throop [Page 6]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
difficult to determine which PLE entry
should count the failure. In such cases the
first likely entry in this table should be
selected. Agents should record the failure
even if they are unsure which PLE should be
associated with the failure."
::= { mioxPleEntry 3 }
mioxPleLastFailedEnAddr OBJECT-TYPE
SYNTAX OCTET STRING (SIZE(2..128))
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The last Encapsulated address that failed
to find a corresponding X.121 address and
caused mioxPleEnAddrToX121LkupFlrs to be
incremented. The first octet of this object
contains the encapsulation type, the
remaining octets contain the address of that
type that failed. Thus for an IP address,
the length will be five octets, the first
octet will contain 204 (hex CC), and the
last four octets will contain the IP
address. For a snap encapsulation, the
first byte would be 128 (hex 80) and the
rest of the octet string would have the snap
header."
::= { mioxPleEntry 4 }
mioxPleEnAddrToX121LkupFlrTime OBJECT-TYPE
SYNTAX TimeTicks
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The most recent value of sysUpTime when the
translation from an Encapsulated Address to
X.121 address failed to find a corresponding
X.121 address."
::= { mioxPleEntry 5 }
mioxPleX121ToEnAddrLkupFlrs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times the translation from an
X.121 address to an Encapsulated Address
Throop [Page 7]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
mioxPleQbitFailureTime OBJECT-TYPE
SYNTAX TimeTicks
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The most recent value of sysUpTime when a
connection was closed because of a Q-bit
failure. This will also be the last time
that mioxPleQbitFailures was incremented."
::= { mioxPleEntry 11 }
mioxPleMinimumOpenTimer OBJECT-TYPE
SYNTAX PositiveInteger
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The minimum time in milliseconds this
interface will keep a connection open before
allowing it to be closed. A value of zero
indicates no timer."
DEFVAL { 0 }
::= { mioxPleEntry 12 }
mioxPleInactivityTimer OBJECT-TYPE
SYNTAX PositiveInteger
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The amount of time time in milliseconds
this interface will keep an idle connection
open before closing it. A value of
2147483647 indicates no timer."
DEFVAL { 10000 }
::= { mioxPleEntry 13 }
mioxPleHoldDownTimer OBJECT-TYPE
SYNTAX PositiveInteger
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The hold down timer in milliseconds. This
is the minimum amount of time to wait before
trying another call to a host that was
previously unsuccessful. A value of
2147483647 indicates the host will not be
retried."
DEFVAL { 0 }
::= { mioxPleEntry 14 }
Throop [Page 9]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
mioxPleCollisionRetryTimer OBJECT-TYPE
SYNTAX PositiveInteger
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The Collision Retry Timer in milliseconds.
The time to delay between call attempts when
the maximum number of circuits is exceeded
in a call attempt."
DEFVAL { 0 }
::= { mioxPleEntry 15 }
mioxPleDefaultPeerId OBJECT-TYPE
SYNTAX InstancePointer
ACCESS read-write
STATUS mandatory
DESCRIPTION
"This identifies the instance of the index
in the mioxPeerTable for the default
parameters to use with this interface.
The entry identified by this object may have
a zero length Encapsulation address and a
zero length X.121 address.
These default parameters are used with
connections to hosts that do not have
entries in the mioxPeerTable. Such
connections occur when using ddn-x25 IP-X.25
address mapping or when accepting
connections from other hosts not in the
mioxPeerTable.
The mioxPeerEncTable entry with the same
index as the mioxPeerTable entry specifies
the call encapsulation types this PLE will
accept for peers not in the mioxPeerTable.
If the mioxPeerEncTable doesn't contain any
entries, this PLE will not accept calls from
entries not in the mioxPeerTable."
::= { mioxPleEntry 16 }
-- ###########################################################
-- Peer Table
-- ###########################################################
Throop [Page 10]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
ACCESS read-only
STATUS mandatory
DESCRIPTION
"An index value that distinguished one entry
from another. This index is independent of
any other index."
::= { mioxPeerEntry 1 }
-- Systems can claim conformance with this MIB without
-- implementing sets to mioxPeerStatus with a value of
-- clearCall or makeCall.
-- All other defined values must be accepted.
-- Implementors should realize that allowing these values
-- provides richer management, and implementations
-- are encouraged to accept these values.
mioxPeerStatus OBJECT-TYPE
SYNTAX INTEGER {
valid (1),
createRequest (2),
underCreation (3),
invalid (4),
clearCall (5),
makeCall (6)
}
ACCESS read-write
STATUS mandatory
DESCRIPTION
"This reports the status of a peer entry.
A value of valid indicates a normal entry
that is in use by the agent. A value of
underCreation indicates a newly created
entry which isn't yet in use because the
creating management station is still setting
values.
The value of invalid indicates the entry is
no longer in use and the agent is free to
delete the entry at any time. A management
station is also free to use an entry in the
invalid state.
Entries are created by setting a value of
createRequest. Only non-existent or invalid
entries can be set to createRequest. Upon
receiving a valid createRequest, the agent
will create an entry in the underCreation
state. This object can not be set to a
value of underCreation directly, entries can
Throop [Page 12]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
only be created by setting a value of
createRequest. Entries that exist in other
than the invalid state can not be set to
createRequest.
Entries with a value of underCreation are
not used by the system and the management
station can change the values of other
objects in the table entry. Management
stations should also remember to configure
values in the mioxPeerEncTable with the same
peer index value as this peer entry.
An entry in the underCreation state can be
set to valid or invalid. Entries in the
underCreation state will stay in that state
until 1) the agent times them out, 2) they
are set to valid, 3) they are set to
invalid. If an agent notices an entry has
been in the underCreation state for an
abnormally long time, it may decide the
management station has failed and invalidate
the entry. A prudent agent will understand
that the management station may need to wait
for human input and will allow for that
possibility in its determination of this
abnormally long period.
Once a management station has completed all
fields of an entry, it will set a value of
valid. This causes the entry to be
activated.
Entries in the valid state may also be set
to makeCall or clearCall to make or clear
X.25 calls to the peer. After such a set
request the entry will still be in the valid
state. Setting a value of makeCall causes
the agent to initiate an X.25 call request
to the peer specified by the entry. Setting
a value of clearCall causes the agent to
initiate clearing one X.25 call present to
the peer. Each set request will initiate
another call or clear request (up to the
maximum allowed); this means that management
stations that fail to get a response to a
set request should query to see if a call
was in fact placed or cleared before
Throop [Page 13]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
retrying the request. Entries not in the
valid state can not be set to makeCall or
clearCall.
The values of makeCall and clearCall provide
for circuit control on devices which perform
Ethernet Bridging using static circuit
assignment without address recognition;
other devices which dynamically place calls
based on destination addresses may reject
such requests.
An agent that (re)creates a new entry
because of a set with createRequest, should
also (re)create a mioxPeerEncTable entry
with a mioxPeerEncIndex of 1, and a
mioxPeerEncType of 204 (hex CC)."
::= { mioxPeerEntry 2 }
mioxPeerMaxCircuits OBJECT-TYPE
SYNTAX PositiveInteger
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The maximum number of X.25 circuits allowed
to this peer."
DEFVAL { 1 }
::= { mioxPeerEntry 3 }
mioxPeerIfIndex OBJECT-TYPE
SYNTAX PositiveInteger
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value of the ifIndex object for the
interface to X.25 to use to call the peer."
DEFVAL { 1 }
::= { mioxPeerEntry 4 }
mioxPeerConnectSeconds OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of seconds a call to this peer
was active. This counter will be
incremented by one for every second a
connection to a peer was open. If two calls
Throop [Page 14]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
are open at the same time, one second of
elapsed real time will results in two
seconds of connect time."
::= { mioxPeerEntry 5 }
mioxPeerX25CallParamId OBJECT-TYPE
SYNTAX InstancePointer
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The instance of the index object in the
x25CallParmTable from RFC 1382 for the X.25
call parameters used to communicate with the
remote host. The well known value {0 0}
indicates no call parameters specified."
DEFVAL { {0 0} }
::= { mioxPeerEntry 6 }
mioxPeerEnAddr OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (0..128))
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The Encapsulation address of the remote
host mapped by this table entry. A length
of zero indicates the remote IP address is
unknown or unspecified for use as a PLE
default.
The first octet of this object contains the
encapsulation type, the remaining octets
contain an address of that type. Thus for
an IP address, the length will be five
octets, the first octet will contain 204
(hex CC), and the last four octets will
contain the IP address. For a snap
encapsulation, the first byte would be 128
(hex 80) and the rest of the octet string
would have the snap header."
DEFVAL { ''h }
::= { mioxPeerEntry 7 }
mioxPeerX121Address OBJECT-TYPE
SYNTAX X121Address
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The X.25 address of the remote host mapped
Throop [Page 15]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
by this table entry. A zero length string
indicates the X.25 address is unspecified
for use as the PLE default."
DEFVAL { ''h }
::= { mioxPeerEntry 8 }
-- Systems can claim conformance to this MIB without
-- implementing sets to mioxPeerX25CircuitId.
-- However systems that use PVCs with RFC1356
-- are encouraged to implement sets.
mioxPeerX25CircuitId OBJECT-TYPE
SYNTAX InstancePointer
ACCESS read-write
STATUS mandatory
DESCRIPTION
"This object identifies the instance of the
index for the X.25 circuit open to the peer
mapped by this table entry. The well known
value {0 0} indicates no connection
currently active. For multiple connections,
this identifies the index of a multiplexing
table entry for the connections. This can
only be written to configure use of PVCs
which means the identified circuit table
entry for a write must be a PVC."
DEFVAL { {0 0} }
::= { mioxPeerEntry 9 }
mioxPeerDescr OBJECT-TYPE
SYNTAX DisplayString (SIZE (0..255))
ACCESS read-write
STATUS mandatory
DESCRIPTION
"This object returns any identification
information about the peer. An agent may
supply the comment information found in the
configuration file entry for this peer. A
zero length string indicates no information
available."
DEFVAL { ''h }
::= { mioxPeerEntry 10 }
-- ###########################################################
-- Peer Encapsulation Table
-- ###########################################################
Throop [Page 16]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
mioxPeerEncTable OBJECT-TYPE
SYNTAX SEQUENCE OF MioxPeerEncEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"This table contains the list of
encapsulations used to communicate with a
peer. This table has two indexes, the first
identifies the peer, the second
distinguishes encapsulation types.
The first index identifies the corresponding
entry in the mioxPeerTable. The second
index gives the priority of the different
encapsulations.
The encapsulation types are ordered in
priority order. For calling a peer, the
first entry (mioxPeerEncIndex of 1) is tried
first. If the call doesn't succeed because
the remote host clears the call due to
incompatible call user data, the next entry
in the list is tried. Each entry is tried
until the list is exhausted.
For answering a call, the encapsulation type
requested by the peer must be found the list
or the call will be refused. If there are
no entries in this table for a peer, all
call requests from the peer will be refused.
Objects in this table can only be set when
the mioxPeerStatus object with the same
index has a value of underCreation. When
that status object is set to invalid and
deleted, the entry in this table with that
peer index must also be deleted."
::= { mioxPeer 2 }
mioxPeerEncEntry OBJECT-TYPE
SYNTAX MioxPeerEncEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Per connection information."
INDEX { mioxPeerIndex, mioxPeerEncIndex}
::= { mioxPeerEncTable 1 }
Throop [Page 17]

RFC 1461 Multiprotocol Interconnect on X.25MIB May 1993
MioxPeerEncEntry ::= SEQUENCE {
mioxPeerEncIndex
PositiveInteger,
mioxPeerEncType
INTEGER
}
mioxPeerEncIndex OBJECT-TYPE
SYNTAX PositiveInteger
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The second index in the table which
distinguishes different encapsulation
types."
::= { mioxPeerEncEntry 1 }
mioxPeerEncType OBJECT-TYPE
SYNTAX INTEGER (0..256)
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value of the encapsulation type. For
IP encapsulation this will have a value of
204 (hex CC). For SNAP encapsulated
packets, this will have a value of 128 (hex
80). For CLNP, ISO 8473, this will have a
value of 129 (hex 81). For ES-ES, ISO 9542,
this will have a value of 130 (hex 82). A
value of 197 (hex C5) identifies the Blacker
X.25 encapsulation. A value of 0,
identifies the Null encapsulation.
This value can only be written when the
mioxPeerStatus object with the same
mioxPeerIndex has a value of underCreation.
Setting this object to a value of 256
deletes the entry. When deleting an entry,
all other entries in the mioxPeerEncTable
with the same mioxPeerIndex and with an
mioxPeerEncIndex higher then the deleted
entry, will all have their mioxPeerEncIndex
values decremented by one."
::= { mioxPeerEncEntry 2 }
-- ###########################################################
END
Throop [Page 18]